What is the quality of drug therapy clinical practice guidelines in Canada?

BACKGROUND: The Canadian Medical Association maintains a national online database of clinical practice guidelines developed, endorsed or reviewed by Canadian organizations within 5 years of the current date. This study was designed to identify and describe guidelines in the database that make recommendations related to the use of drug therapy, and to assess their quality using a standardized guideline appraisal instrument. METHODS: Drug therapy guidelines in the database were identified with the use of search terms and hand searching. Descriptive information about the developers, endorsement by other organizations, publication status, disease and drug focus was abstracted. Each guideline was independently assessed by 3 appraisers (a physician, a pharmacist and a methodologist) with the use of the Appraisal Instrument for Clinical Guidelines. Conditions were classified according to the tenth revision of the International Statistical Classification of Diseases and Related Health Problems. RESULTS: We identified 217 drug therapy guidelines produced or reviewed from 1994 to 1998. Guideline developers included national organizations (47.0%), paragovernment organizations (39.6%) and professional associations (30.9%); 31.3% of the guidelines were published, and 10.6% stated drug company sponsorship. The most common conditions addressed by the guidelines were infections and parasitic diseases (39.6%), neoplasms (11.5%) and diseases of the circulatory system (11.5%). Drugs most commonly cited were anti-infective agents (42.9%), antiviral agents (15.2%) and cardiovascular drugs (16.1%). Eleven organizations produced 176 (81.1%) of the guidelines. In all, 14.7% of the guidelines met half or more of the 20 items assessing rigour of guideline development on the appraisal instrument (mean quality score 30.0% [95% confidence interval (CI) 27.5%-32.6%]), 61.8% met half or more of the 12 items assessing guideline context and content (mean score 57.0% [95% CI 54.6%-59.3%]), and none met half or more of the 5 items assessing guideline application (mean score 5.6% [95% CI 4.7%-6.5%]). Overall, 64.6% of the guidelines were recommended with modification by at least 2 of the 3 appraisers, 9.2% were recommended without change, and 26.3% were not recommended. The quality of the guidelines assessed varied significantly by developer, publication status and drug company sponsorship. No substantial improvement in guideline quality was observed over the 5-year study period. INTERPRETATION: Developers of Canadian drug therapy guidelines are producing guidelines that are often perceived to be clinically useful to physicians and pharmacists, although the methods (or the description of the methods) by which they are developed need to be more rigorous and thorough.

Survival after percutaneous endoscopic gastrostomy placement in older persons.

BACKGROUND: The prolongation of life is an important consideration in the decision to initiate long-term tube feeding. This report critically synthesizes the evidence regarding the impact of percutaneous endoscopic gastrostomy (PEG) tube placement on survival in older persons. METHODS: A systematic search was conducted using MEDLINE from January 1980 until January 1999. Articles reporting survival data in older persons (mean or median age >65 years) after PEG tube placement were identified. The number and age of subjects, length of follow-up, setting, and survival data were extracted from all eligible studies. Mortality data at 1, 2, 6, and 12 months after PEG placement were quantitatively synthesized. Clinical characteristics associated with decreased survival among subjects with PEG tubes were identified. RESULTS: Five cohort studies compared survival in patients with and without feeding tubes in nursing homes, but none demonstrated a survival benefit. Another cohort study reported increased survival for tube-fed patients with amyotrophic lateral sclerosis. The pooled proportion of all subjects surviving after PEG placement was as follows: 1 month = 0.81 (95% confidence interval [CI], 0.74-0.88), 2 months = 0.70 (95% CI, 0.65-0.74), 6 months = 0.56 (95% CI, 0.20-0.92), and 12 months = 0.38 (95% CI, 0.26-0.49). Advanced age and malignancy were the factors most often reported to be associated with poorer survival among subjects with PEG tubes. CONCLUSIONS: The impact of PEG placement on survival is not known because the level of evidence is limited. PEG tubes may prolong life in selected populations. However, the majority of older patients selected for PEG placement will not survive 1 year after the procedure. Certain factors may identify those patients more likely to derive a survival benefit from long-term tube feeding. This information may offer some guidance to decision makers for whom prolongation of life is an important factor in the tube-feeding decision.

A comparison of clinical practice guideline appraisal instruments.

OBJECTIVE: To identify and compare clinical practice guideline appraisal instruments. METHODS: Appraisal instruments, defined as instruments intended to be used for guideline evaluation, were identified by searching MEDLINE (1966-99) using the Medical Subject Heading (MeSH) practice guidelines, reviewing bibliographies of the retrieved articles, and contacting authors of guideline appraisal instruments. Two reviewers independently examined the questions/statements from all the instruments and thematically grouped them. The 44 groupings were collapsed into 10 guideline attributes. Using the items, two reviewers independently undertook a content analysis of the instruments. RESULTS: Fifteen instruments were identified, and two were excluded because they were not focused on evaluation. All instruments were developed after 1992 and contained 8 to 142 questions/statements. Of the 44 items used for the content analysis, the number of items covered by each instrument ranged from 6 to 34. Only the instrument by Cluzeau and colleagues included at least one item for each of the 10 attributes, and it addressed 28 of the 44 items. This instrument and that of Shaneyfelt et al. are the only instruments that have so far been validated. CONCLUSIONS: A comprehensive, concise, and valid instrument could help users systematically judge the quality and utility of clinical practice guidelines. The current instruments vary widely in length and comprehensiveness. There is insufficient evidence to support the exclusive use of any one instrument, although the Cluzeau instrument has received the greatest evaluation. More research is required on the reliability and validity of existing guideline appraisal instruments before any one instrument can become widely adopted.